Diphenyl derivative



Patented Oct. 4, 1938 DIPHENYL DERIVATIVE Sebastian Gassner and BertholdBienert, Leverkusen-I. G. Werk, Germany, assignors to General AnilineWorks, Inc., New York, N. Y., a corporation of Delaware No Drawing.Application February 12, 1937, Se-

rial No. 125,433. In Germany October 23,

1 Claim.

The present invention is concerned with the preparation of3,4-dicyanodipheny1 which represents a valuable intermediate product,for instance, for the preparation of dyestufis.

The preparation of 3,4-dicyanodiphenyl has 3 been described first in ourco-pending applica- V 1 part ofthe sodium or potassium salt of the tionSer. No. 106,829, filed October 21, 1936, and -cya p -su f c d a d 2parts of in this respect the present invention is to be conanhydrouspotassium ferrocyanide are gradually sidered as a continuation in partapplication of heated in a vacuum subliming' apparatus to a the saidearier application. According to applip r t e of about C- After having p10 cation No. 106,829 the 3,4-dicyanodiphenyl can be the reactionmixture for a prolonged time at this obtained by starting from3-nitro-4-aminodiphetemperature (for' about 10 hours) it is heated tonyl, converting the amino group into the cyanic 340 .C., the3,4-dicyanodiphenyl thus formed group according to the Sandmeyersreaction and subliming thereby; 80% of the reaction product thenreducing the nitro group to the amino group are obtained which onrecrystallizing from 5 times 15 whereupon the latter is transformed intothe, its quantity of benzenerepresents leaflets of a cyanic group. Wehave furthermore found that melting point 015161-162" C. V the3,4-dicyanodipheny1 can be obtained in a Similar results are obtainedwhen using potasgood yield by heating 4-cyanodiphenyl-3-sulfonic siumcyanide instead of potassium ferrocyanide. V

acid, preferably inform of its alkali metal salt, The4-cyanodiphenyl-3-sulfonic acid can be 20 with salts of the ferrocyanicacid or of hydroobtained by heating 4-aminodiphenyl together cyanic acidwhich are suitably employed as alkali with chlorosulfonic acid ino-dichlorobenzene and metal salts. The reaction may be performed atreplacing the amino group by the'oyanic group a temperature betweenabout 250 to about 340 0. according to the Sandmeyers reaction.

5 The 3,4-dicyanodiphenyl formed by this reaction We claim:

can be isolated from the reaction mixture by subliming at about 340 C.The 3,4-dicyanodiphenyl can be recrystallized from benzene and has in apure state the melting point of 161-162 0.

The following example illustratesthe invention without, however,restricting it thereto (the parts 7 being by weight) Example As a newproduct, 3,4-dicyanodiphenyl.

SEBASTIAN GASSNER. 5

BERTHOLD BIENERT.

